Hydraulic rotary underreamer



Aug. 4, 1925. 1,548,578

B. F. BLANCHARD HYDRAULIC ROTARY UNDERREAMER Filed June 9. 1922 2 Sheets-Sheet l 7% I I .1 )4 9 3o 9 '9 3 L y 3/,/

0 IL 25 n 26 5 2 .mt'. 2 27 4 2g 35' Aug. 4, 1925. 1,548,578

B. F. BLANCHARD HYDRAULIC ROTARY UNDERREAMER Filed June 9, 1922 2 Sheets-Sheet 2 n w' *1, g'I 2U" lg Lilu Patented Aug. 4, 1925.-

I To all whom it may concern:

1,548,578 PATENT oFFicE.

BENJAMIN: BLANCHARD, F BREA, CALIFORNIA.

, fiajvnrcaumcnoramr :UNDERREAMER.

' I "lpplication filed l'une' J9,

' Be 't known that I, BENJAMIN F. BLANCiIARD, a citizen of the United States, residing at "Bi-ea, in the county of Orange and State of California, have invented new i and useful Improvements'in'Hydraulic Rotary Underreamers, of which the following is a specification. I w This invention relates to deep -well drilling tools and more particularly to underreamers. It is an object of the present invention to provide a hydraulically set underreamer fmechanism. Another object of the invencompanying drawings, in which Figure 1 is a central longitudinal section of the 'underreaming tool its" retracted or collapsed position.

'Fig. 2 isa longitudinal central sectionfof the tool showing the underreamers in the expanded position. 1 .Fig. 3 is a longitudinalsection of the underreamer body. i Fig. 4 is a cross section on line 4 -4 of Fig. 3 with the underreamer slides and cutters removed. a

Fig. 5 is a side elevationand partial sec- I tion'of the tool as combined ,with a fish 'tail bit showing the installation in a well hole. 1 v

Fig. 6 is a transverse section on line 6 6' of Fig. 2.

Fig. 7 is an edge view of one of the detached cutter slides. i V M Fig; 8 is a side elevation of the inner face of a cutter slide. v p

Fig. 9 is a side elevation looking toward I the end of thefdetached slide operating pis- Fig. 10 is a broadside elevation of the piston.

In its preferred embodiment, the present invention consists of a body member comprising. an upper taper threadedgattachmg neck 2 provided with anaxial bore 3, the

upper portion of'which is enlarged and in- 1922'. Serial No. 566,950.-

' ternally threaded as at 4. Below the neck 2 the body consists of a cylindrical shank 5 diametrically channeled from side to side to form a slide space6 which has flat side walls 7 suitably spaced to receive slides 8. The shank portion 5 has downwardly and inwardly convergent outer faces 9 upon whichthe inner fiat faces 8 of the slides 8 hear. The outer faces 8 of the slides may be curved .on arcs concentric to the center of the shank 5, and the lateral faces of the slides 8 are provided with gibs or longitudi'nal flanges 8, and these incline with re-' spect to thelouter faces 8 andare parallel to the inner-faces 8 of the slides, so that when the slides are respectively applied'z to the opposite inclined faces 9 of the body shank, the slides can be shifted along the inclined faces, and such action will result in the inward and outward movement of the slides. V

The gibs 8 of the slides are designed to enter the, open upper ends of channels or guideways .7 formed in the side-faces .7 of

the chamber 6. The convergent guide faces- 9 of the shank body' terminate somewhat above the bottom of the chamber 6 andthus provide for vertical movement "in the chamber of means for actuating the slides .8.

" Below the body portion having the convergent side 'faces 9 9, the body is provided with a tubular shell 10 having an open mouth 11 leading into the chamber 6 in. thebody shank. The lower end of-the sleeve 10 is provided with internal threads 12, and below these are joint receiving tapered threads 13 towhich may be attached any tool joint 14 which may carry a bit, for instance a fish tail bitl5, i 5.

Fitting in the mouth 11 1s an inverted thiinble 16, the lower end of which is supported on an adjusting jack screw 17 mountedin a plate 18 resting in the threads 12 of the sleeve 10. The plate 18 is apertured as at-18 to permit of the circulation of water in the usual manner. Slidably fitting the thimble 16 is a .piston 20 having a tu- 'bular piston rod 21, on the upper end of which is fixed a coupling or cross head 22 having transverse lips 23 tojenter transverse channels 8 in the inner faces of-the opposed slides 8. The slides interlock with the head 22 of the piston when this latter is exposed in the chamberG in the body shank 5 and. whenithe slides are slipped down the converg'ent guideways 7 to a position as is inupper portion of the pipe 25.

dicated in Fig. 2, then downward movement of the slides contracts them more and they become thoroughly coupled with the ad jacent head of the piston which becomes an actuating device for the slides.

The tubular piston rod 21 sli-dably fits upon a pipe or tube 25, the upper end of which projects above the neck 2 ofthe body, and is provided with a packing gland 26 entering a bushing 27 which is applied to the threads 4'in the body neck. The gland 26 serves to engage a collar 28 fixed on the The lower end of thepipe 25 extends below the piston 20 whenthe latter'is in its lowermost position as is seen in Fig. l, and adjacent the lower end of the pipe is a set of ports 25 which, when the piston is in its lower position, provides for the escape of water entering through a fitting 30 attached to the neck of the reamer body (Fig. 2). The water passing from the ports 25 enters a chamber 20 in the piston and bleeds therefrom through upwardly directed bleed ports 20, and thence passes into the thimble from which it escapes at the mouth into the open chamber 6.

The slides 8 are each provided in their outer faces with pockets 8 of suitable proportions to receive reaming tools. In the present case these tools consist of substantially cylindrical cutters 31 having longitudinal cutting teeth on the periphery, and which teeth preferably converge 0r taper on the ends of thecut-ters, as shown clearly in Figs. 1 and 2. The cutters are mounted upon spindles 32, the ends of which are mounted in the contiguous walls at the ends of thepockets in the slides 8. The slides and cutters are'of such proportions that they may be'contracted to a position substantially 'within the side lines of the body sleeve 10,

, and this will enable the lowering of the tool into the well casing C, Fig. 5.

After the tool has thus been positioned below the well casing end, it is necessary to expand the slides 8 and to thrust the cutters 31 outwardly into effective position to ream the well hold. To that end, fluid under pressure is turned into the drilling pipe P, Fig. 5, and from thence it will pass into the fitting 30, and from this into the pipe 25, from which it will accumulate in the bottom of the thimble 21 and react against "the piston 20. When sufficient pressure has accumulated against the piston, this will be forced upwardly, and by virtue of its connection with the slides 8, these will be forced out- 'wardly to the position shown in F ig. 2 in whichthey have been forced up along the slide faces 9 of the underreamer body and outwardly at the'same time. The upward movement of the cutters is limited and the strain-of operation [is taken by removable chock blocks-33 which are applied to the I ters.

side faces 9 of the underreamer body and may be removably held as by screws 34 or other means. i The slides are normally subjected to the downward pressure of a substantial spring 35 surrounding the pressure supply .pipe 25 and contained in the bore 3 of the cutter neck. Thus, when it is desired to lift the string of tools from the well, the hydraulic or other fluid pressure transmitted to the thimble 20 being removed, permits the spring 35 to function and press the piston 20 with the attached cutter bearing slides 8 down and, therefore, effect the retraction of the cutters.

In the expanded position of the cutters as shown in Fig. 2, the piston 20 occupiesa position somewhat above 'a series of aper-. tures 16' provided in the thimble l6, and the excess and circulating water supplied by the pressure supply pipe 25 may then escape from the thimble piston chamber through the outlets l6, and thence through the perforated plate 18 to the bottom of the well.

It is desirable to provide for the reception of water that may be encountered in the well as the tool is lowered, and to that end the fittin 30 is provided with inlet check valves 30 above the neck 2 of the underreamer body, and, therefore, in the absence of pressure in the string of tool parts, the well water may enter through the check valves 30 and accumulate in the chambers of the sPring. When hydraulic operating pressure is turned into the tool string, then the check valves 30 automatically seatand the operating pressure becomes effective upon the'piston 20 to actuate and set the underreaming cutters 31. 1

When it becomes desirable to pull the tool from the well, the water in the column will be permitted to drain or bleed out into the well hole through the bleeding apertures 20. This prevents the drillers from bein showered with water during the uncoup ing; of the sectionsas they are disconnected.

Various modifications and changes may be resorted to within the spirit of the invention as claimed.

What is claimed is:

1. An underreamer comprising, in combination, a set of retractive cutters, hydraulically operative means for projecting the cutters to active position, said means including a piston operatively connected to the cutters, said piston having a'stem forming a motive fluid conduit, a piston chamber in which the piston operates and into which the conduit discharges, and spring means mounted on the stem for retracting'the cut- 2..An underreamercomprising, in comhydraulic pressure may be created, underreaming cutters mounted for retraction and expansion in the underreamer body, hydraulically operated means in the body for setting the cutters, and a fitting connectingthe tool string and the underreamer" body and haying means for admitting well water to the chambers thereof.

3. An underreamer comprising, in combination a body having means for attachment to a string of tool parts in which hydraulic pressure may be created, underreaming cutters mounted for retraction and expansion in the underreamer body, hydraulically operatod means in the body for setting the cutters, and a fitting connecting the tool string and the underreamer body and having means for admitting well water to the chambers thereof, said means comprising outwardly seating check valves for maintaining a hydraulic pressure in the tool string to effect the actuation of the underreaming cutters,

4. An underreamer comprising a body having means for attachment to a string of tool parts, the body being provided with opposite convergent faces, slides guidable along said faces to be moved inwardly concurrently and outwardly concurrently, cutters. mounted on said slides to be operative in the outer position of the slides, and means within the underreamer body for shifting the slides to move the cutters to effective and ineffective positions, said means including a hydraulically operative hollow piston having operative connections with said slides, and a motive fluid conduit on which said piston is slidably mounted.

5. An underreamer comprising a body having means for attachment to a string of tool parts, the body being provided with opposite convergent faces, slides guidable along said faces to be moved inwardly concurrently and outwardly concurrently, cutters mounted on said slides to be operative in the outer position of the slides, means within the underreamer body for shifting the slides to move the cutters to effective and ineffective positions, said means including a hydraulically operative hollow piston having operative connections with said slides, and a pressure supply pipe extending through and on which said piston is slidably mounted and by which pressure fluid is conveyed to be operative upon the piston.

In testimony whereof I have signed my name to this specification.

B. F. BLANCHARD 

